Sex differences in mental stress-induced myocardial ischemia in young survivors of an acute myocardial infarction.

OBJECTIVES: Emotional stress may disproportionally affect young women with ischemic heart disease. We sought to examine whether mental stress-induced myocardial ischemia (MSIMI), but not exercise-induced ischemia, is more common in young women with previous myocardial infarction (MI) than in men.
METHODS: We studied 98 post-MI patients (49 women and 49 men) aged 38 to 60 years. Women and men were matched for age, MI type, and months since MI. Patients underwent technetium-99m sestamibi perfusion imaging at rest, after mental stress, and after exercise/pharmacological stress. Perfusion defect scores were obtained with observer-independent software. A summed difference score (SDS), the difference between stress and rest scores, was used to quantify ischemia under both stress conditions.
RESULTS: Women 50 years or younger, but not older women, showed a more adverse psychosocial profile than did age-matched men but did not differ for conventional risk factors and tended to have less angiographic coronary artery disease. Compared with age-matched men, women 50 years or younger exhibited a higher SDS with mental stress (3.1 versus 1.5, p = .029) and had twice the rate of MSIMI (SDS ≥ 3; 52% versus 25%), whereas ischemia with physical stress did not differ (36% versus 25%). In older patients, there were no sex differences in MSIMI. The higher prevalence of MSIMI in young women persisted when adjusting for sociodemographic and life-style factors, coronary artery disease severity, and depression.
CONCLUSIONS: MSIMI post-MI is more common in women 50 years or younger compared with age-matched men. These sex differences are not observed in post-MI patients who are older than 50 years.